Light-emitting device

ABSTRACT

A light-emitting device has a light-emitting element including first and a second semiconductor light-emitting structures, each having a first and a second electrode, and a substrate supporting the light-emitting element. The substrate has an interconnection layer having a first interconnection portion comprising a first land, a second interconnection portion comprising second and third lands, and a third interconnection portion comprising a fourth land, and a first reflective member covering a portion of the interconnection layer. A portion of the first land is coupled to the first electrode of the first semiconductor light-emitting structure. A portion of the second land and a portion of the third land are coupled to the second electrode of the first semiconductor light-emitting structure and the first electrode of the second semiconductor light-emitting structure, respectively. A portion of the fourth land is coupled to the second electrode of the second semiconductor light-emitting structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No.2019-062610, filed on Mar. 28, 2019, and Japanese Patent Application No.2019-180584, filed on Sep. 30, 2019, the disclosures of which are herebyincorporated by reference in their entireties.

BACKGROUND

The present disclosure relates to light-emitting devices.

Japanese Patent Publication No. 2002-270905 discloses a compositelight-emitting element in which a block light-emitting element includinga plurality of light-emitting elements formed by depositing a GaNcompound semiconductor on a common sapphire substrate is mounted on asubmount element. As can be understood from the description of JapanesePatent Publication No. 2002-270905 (e.g., paragraphs [0004] and [0005]),it is generally advantageous to form a plurality of light-emittingstructures of a GaN compound semiconductor, each of which includes anactive layer, on a common sapphire substrate, in terms of obtaining alarger luminous flux, compared to the configuration in which a singlelight-emitting structure is formed on a sapphire substrate.

The submount element disclosed in Japanese Patent Publication No.2002-270905 is formed of a silicon substrate, and has an n-electrodepattern and a p-electrode on an upper surface thereof. Each of theplurality of light-emitting elements in the block light-emitting elementis mounted on the submount element by electrodes provided on theopposite side from the sapphire substrate being bonded by bumps to theelectrode patterns on the submount element.

SUMMARY

In an element having a plurality of semiconductor light-emittingstructures electrically independent of each other, like the blocklight-emitting element disclosed in Japanese Patent Publication No.2002-270905, it is advantageous to verify the presence or absence ofleakage current in each of the plurality of semiconductor light-emittingstructures individually after the plurality of semiconductorlight-emitting structures are mounted on a support (e.g., a submountelement) having an electrode pattern.

A light-emitting device according to an embodiment of the presentdisclosure includes: a light-emitting element having an upper surface,and including a plurality of semiconductor light-emitting structureseach having a first and a second electrode having different polarities,disposed on the opposite side from the upper surface of thelight-emitting element, and electrically separated from each other; anda substrate supporting the light-emitting element. The plurality ofsemiconductor light-emitting structures include a first and a secondsemiconductor light-emitting structure. The substrate has aninterconnection layer having a land pattern including a firstinterconnection portion on which a first land is provided, a secondinterconnection portion on which a second and a third land are provided,and a third interconnection portion on which a fourth land is provided,and a first reflective member covering a portion of the interconnectionlayer and having an opening. The light-emitting element is locatedinside the opening of the first reflective member as viewed from above.A portion of the first land of the first interconnection portion isexposed in the opening of the first reflective member, and is coupled tothe first electrode of the first semiconductor light-emitting structure.A portion of the second land and a portion of the third land, of thesecond interconnection portion, are exposed inside the opening of thefirst reflective member, and are coupled to the second electrode of thefirst semiconductor light-emitting structure and the first electrode ofthe second semiconductor light-emitting structure, respectively. Aportion of the fourth land of the third interconnection portion isexposed inside the opening of the first reflective member, and iscoupled to the second electrode of the second semiconductorlight-emitting structure.

According to certain embodiments of the present disclosure, provided isa light-emitting device in which each of a plurality of semiconductorlight-emitting structures included in a light-emitting element can beeasily inspected even after the light-emitting element is mounted on asupport having an electrode pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic enlarged top view showing a light-emitting elementand surroundings of a light-emitting device according to an embodimentof the present disclosure.

FIG. 2 is a schematic cross-sectional view of the light-emitting deviceof the embodiment of the present disclosure.

FIG. 3 is a schematic top perspective view of the light-emitting elementof FIGS. 1 and 2.

FIG. 4 is a schematic cross-sectional view of the light-emitting elementof FIG. 3 taken parallel to the YZ plane of FIG. 3.

FIG. 5 is a diagram showing an equivalent circuit of the light-emittingdevice of FIGS. 1 and 2.

FIG. 6 is a schematic cross-sectional view showing a variation of thelight-emitting device of the embodiment of the present disclosure.

FIG. 7 is a schematic cross-sectional view showing another variation ofthe light-emitting device of the embodiment of the present disclosure.

FIG. 8 is a schematic top view showing still another variation of thelight-emitting device of the embodiment of the present disclosure.

FIG. 9 is a schematic top view showing still another variation of thelight-emitting device of the embodiment of the present disclosure.

FIG. 10 is a schematic top view showing still another variation of thelight-emitting device of the embodiment of the present disclosure.

FIG. 11 is a schematic top view showing still another variation of thelight-emitting device of the embodiment of the present disclosure.

FIG. 12 is a schematic top view showing still another variation of thelight-emitting device of the embodiment of the present disclosure.

FIG. 13 is a schematic cross-sectional view showing still anothervariation of the light-emitting device of the embodiment of the presentdisclosure.

FIG. 14 is a schematic top view showing an example integratedlight-emitting device having a two-dimensional array of thelight-emitting devices of FIG. 13.

FIG. 15 is a schematic cross-sectional view showing another exampleintegrated light-emitting device according to an embodiment of thepresent disclosure.

FIG. 16 is a schematic top view showing a portion of a one-way mirrorused in the integrated light-emitting device of FIG. 15.

FIG. 17 is a schematic cross-sectional view showing still anotherexample integrated light-emitting device according to an embodiment ofthe present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail withreference to the accompanying drawings. The following embodiments areillustrative, and a light-emitting device according to the presentinvention is not limited thereto. For example, the numerical values,shapes, materials, steps, and the order of the steps, etc., indicated inthe following embodiments are merely illustrative, and variousmodifications can be made thereto unless a technical contradictionoccurs. The dimensions, shapes, etc., of elements shown in the drawingsmay be exaggerated for clarity. The dimensions, shapes, etc., of theelements of an actual light-emitting device are not necessarily drawn toscale, e.g., the dimensions of some of the elements of thelight-emitting module relative to the other elements may be exaggerated.Some of the elements may not be shown, in order to avoid unnecessarilyobfuscating the drawings.

In the description that follows, like elements may be denoted by likereference numerals and redundant descriptions may be omitted. Termsindicating specific directions and positions (e.g., “upper,” “lower,”“right,” “left,” and other terms including such terms) may behereinafter used. Note however that these terms are only used forclarity of illustration to refer to relative directions and positions inthe drawings to which reference is made. When applied to drawings,actual products, actual manufacturing apparatuses, etc., other thanthose of the present disclosure, the elements may not have the samearrangement as that shown in the drawings to which reference is made, aslong as the elements have the same directions and positions relative toeach other that are indicated by the terms such as “upper” and “lower”in the drawings to which reference is made. As used herein, the term“parallel” with respect to two straight lines, sides, planes, etc., isintended to encompass some deviations from absolute parallelism (0°)that are in the range of about ±5°, unless otherwise specified. As usedherein, the terms “perpendicular” and “orthogonal” with respect to twostraight lines, sides, planes, etc., are intended to encompass somedeviations from absolute perpendicularity and orthogonality (90°) thatare in the range of about ±5°, unless otherwise specified.

FIGS. 1 and 2 schematically show a light-emitting device according to anembodiment of the present disclosure. For reference, in FIGS. 1 and 2,the X direction, the Y direction, and the Z direction, which areorthogonal to each other, are indicated by arrows. In the other drawingsof the present disclosure, these arrows may be shown. FIG. 1schematically shows an appearance of the light-emitting device of theembodiment of the present disclosure as viewed from above. FIG.schematically shows a cross-section of the light-emitting device of FIG.1 taken parallel to the ZX plane of the figure. The cross-section ofFIG. 2 corresponds to the II-II cross-section of FIG. 1.

The light-emitting device 100A of FIGS. 1 and 2 mainly has alight-emitting element 110A and a substrate 150 supporting thelight-emitting element 110A. As shown in FIG. 2, the substrate 150 hasan upper surface 150 a and a lower surface 150 b located on the oppositeside from the upper surface 150 a, and has an interconnection layer 153Aon the upper surface 150 a. The substrate 150 further has a firstreflective member 154 covering a portion of the interconnection layer153A. Here, the first reflective member 154 has generally a layer-shapedstructure, and has an opening 154 z in a portion thereof. A portion ofthe interconnection layer 153A of the substrate 150 is exposed insidethe opening 154 z of the first reflective member 154.

As shown in FIG. 1, the light-emitting element 110A is disposed insidethe opening 154 z of the first reflective member 154 as viewed fromabove, and is thus mounted on the substrate 150. The light-emittingelement 110A is electrically coupled to the interconnection layer 153Aof the substrate 150 through a bonding member such as solder. Note thatin this example, the entire light-emitting element 110A is disposed in arecess 160 r of a light-transmissive member 160, and is thereby coveredby the light-transmissive member 160.

In the configuration illustrated in FIG. 1, the interconnection layer153A has a land pattern including a first interconnection portion 31, asecond interconnection portion 32, and a third interconnection portion33. The first interconnection portion 31 has a first land L1 as aportion thereof. As used herein, the term “land” refers to anisland-shaped structure having a larger area than that of a linearinterconnect of an interconnection layer. The second interconnectionportion 32 of the interconnection layer 153A has a second land L2, athird land L3, and a connection portion 30. The third interconnectionportion 33 has a fourth land L4. As schematically shown in FIG. 1, thefirst land L1, the second land L2, the third land L3, and the fourthland L4 are each partially exposed in the opening 154 z of the firstreflective member 154. As described below, an electrode of thelight-emitting element 110A is coupled to the first land L1, the secondland L2, the third land L3, and the fourth land L4.

As schematically shown in FIG. 1, a gap G12 is provided between thefirst interconnection portion 31 and the second interconnection portion32. The first land L1 of the first interconnection portion 31 and thesecond land L2 of the second interconnection portion 32 are separatedfrom each other in space by the gap G12 and are thereby electricallyseparated from each other. Likewise, a gap G23 is provided between thesecond interconnection portion 32 and the third interconnection portion33, which are thereby electrically separated from each other. A gap G31is provided between the third interconnection portion 33 and the firstinterconnection portion 31, which are thereby electrically separatedfrom each other. A portion of the gap G12, a portion of the gap G23, anda portion of the gap G31 are also extended inside the opening 154 z ofthe first reflective member 154.

As shown in FIG. 1, a slit-shaped gap G20 is also provided in the secondinterconnection portion 32. By the formation of the gap G20, portions ofthe second land L2 and the third land L3 of the second interconnectionportion 32 that are exposed from the opening 154 z of the firstreflective member 154 are separated from each other in space. Note thatthe second land L2 and the third land L3 are electrically coupled toeach other through the connection portion 30 of the secondinterconnection portion 32, and therefore, have equal potentials.

As shown in FIG. 1, the widths of the gaps G12, G20, G23, and G31between two adjacent ones of the first land L1, the second land L2, thethird land L3, and the fourth land L4 of the interconnection layer 153A,i.e., the distance between two adjacent lands, may be greater on a sidefurther from the light-emitting element 110A than on a side closer tothe light-emitting element 110A. Specifically, a distance GL2 betweentwo adjacent lands in a region covered by the first reflective member154 is greater than a distance GL1 between two adjacent lands in theopening 154 z of the first reflective member 154. In the embodiment ofFIG. 1, in the opening 154 z of the first reflective member 154, thedistance GL1 between two adjacent land is uniform irrespective of thedistance from the light-emitting element 110A. In the opening 154 z ofthe first reflective member 154, a region between two adjacent lands,i.e., the gaps G12, G20, G23, and G31, is not covered by the firstreflective member 154, and therefore, the upper surface 150 a of thesubstrate 150 is exposed in the gaps G12, G20, G23, and G31.

In the embodiment of the present disclosure, a light-emitting element ina light-emitting device has a plurality of semiconductor light-emittingstructures that are electrically independent of each other. For example,the light-emitting element 110A of FIG. 2 includes a first semiconductorlight-emitting structure 111 and a second semiconductor light-emittingstructure 112 that are formed on a common light-transmissive substrate10. As described in detail below with reference to the drawings, thefirst and second semiconductor light-emitting structures, each of whichhas an active layer interposed between an n-type semiconductor layer anda p-type semiconductor layer, emit light when supplied with apredetermined current. For the sake of simplicity, the firstsemiconductor light-emitting structure 111 and the second semiconductorlight-emitting structure 112 are hereinafter referred to as a “firstlight-emitting cell 111” and a “second light-emitting cell 112,”respectively.

Each of the first light-emitting cell 111 and the second light-emittingcell 112 has a positive and a negative electrode on a side of thesubstrate 150 opposite the interconnection layer 153A. As described indetail below with reference to the drawings, the first light-emittingcell 111 has a first electrode (e.g., an n-electrode) and a secondelectrode (e.g., a p-electrode) that have different polarities. Thesecond light-emitting cell 112 also has a first electrode (e.g., ann-electrode) and a second electrode (e.g., a p-electrode) that havedifferent polarities. The first and second electrodes of the firstlight-emitting cell 111 are electrically coupled to the first land L1and the second land L2, respectively, of the interconnection layer 153A.The first and second electrodes of the second light-emitting cell 112are electrically coupled to the third land L3 and the fourth land L4,respectively, of the interconnection layer 153A.

Here, the second land L2 and the third land L3 are a portion of thesecond interconnection portion 32. Therefore, because the secondelectrode of the first light-emitting cell 111 is coupled to the secondland L2, and the first electrode of the second light-emitting cell 112is coupled to the third land L3, the first light-emitting cell 111 andthe second light-emitting cell 112 are electrically coupled together inseries (or in parallel) through the interconnection layer 153A.

In the configuration in which a plurality of light-emitting cellscapable of independently emitting light using a supplied current aredisposed in a single light-emitting element like the light-emittingelement 110A of FIG. 2, it is advantageous to inspect eachlight-emitting cell for a defect, such as leakage current, by measuringa voltage drop or the like. However, in the case in which alight-emitting element includes a plurality of light-emitting cellscapable of operating independently, once the light-emitting element hasbeen mounted on a substrate, the plurality of light-emitting cells inthe light-emitting element are electrically coupled together through aninterconnection layer of the substrate. Therefore, for example, in thecase in which the plurality of light-emitting cells are electricallycoupled together in series through the interconnection layer of thesubstrate, an overall voltage drop of the plurality of light-emittingcells can be measured, but a voltage drop in each individuallight-emitting cell cannot be measured. Specifically, for example, inthe case in which an attempt is made to detect a leakage by applying areverse bias, then even if there is a leakage in one of the plurality oflight-emitting cells, a current may be blocked by the otherlight-emitting cells, so that the leakage cannot be detected. Inaddition, a standard for a measured value is typically set, taking intoaccount the precision of measurement and an individual difference(variations in electrical characteristics) of a light-emitting cell, andtherefore, the measurement of an overall voltage drop in the pluralityof light-emitting cells is unlikely to allow identification of alight-emitting cell having a minute leakage and detection of a defect inthe light-emitting cell.

In contrast, in the embodiment of the present disclosure, for example,the first electrode of the first light-emitting cell 111, the secondelectrode of the first light-emitting cell 111, the first electrode ofthe second light-emitting cell 112, and the second electrode of thesecond light-emitting cell 112 are coupled to the first land L1, thesecond land L2, the third land L3, and the fourth land L4, respectively,provided on the interconnection layer 153A of the substrate 150. Here,the second land L2 and the third land L3 are a part of the common secondinterconnection portion. Therefore, the first light-emitting cell 111and the second light-emitting cell 112 can, for example, be electricallycoupled together in series through the interconnection layer 153A. Insuch a structure, for example, by measuring a voltage drop between thefirst land L1 and the second land L2 of the interconnection layer 153A,the presence or absence of a leakage current in the first light-emittingcell 111 can be investigated. In addition, for example, by measuring avoltage drop between the third land L3 (or the second land L2) and thefourth land L4 of the interconnection layer 153A, the presence orabsence of a leakage current in the second light-emitting cell 112 canbe investigated. Thus, in the state in which the first light-emittingcell 111 and the second light-emitting cell 112 are electrically coupledtogether through the interconnection layer 153A, the presence or absenceof a leakage current in the first light-emitting cell 111, and thepresence or absence of a leakage current in the second light-emittingcell 112, can be verified individually.

Specifically, in the embodiment of the present disclosure, a voltagedrop, etc., can be relatively easily measured for each of the firstlight-emitting cell 111 and the second light-emitting cell 112 in thestate that these cells are coupled together in series, for example.Therefore, the occurrence of a defect such as leakage current can bedetected for each of a plurality of light-emitting cells electricallycoupled together through an interconnection layer of a substrate. Toallow inspection of individual light-emitting cells for electricalcharacteristics contributes to an improvement in the yield andreliability of a light-emitting device.

Each element of the light-emitting device 100A will now be described indetail with reference to the drawings.

[Light-Emitting Element 110A]

FIG. 3 shows the light-emitting element 110A of FIGS. 1 and 2. FIG. 4schematically shows a cross-section of the light-emitting element 110Ataken parallel to the YZ plane of the figure. The cross-section of FIG.4 corresponds to a IV-IV cross-section of FIG. 3.

Each of the light-emitting elements in the light-emitting device of theembodiment of the present disclosure has a plurality of semiconductorlight-emitting structures electrically independent of each other. In theconfiguration illustrated in FIG. 3, the light-emitting element 110Aincludes the light-transmissive substrate 10, the first light-emittingcell 111 (first semiconductor light-emitting structure 111), and thesecond light-emitting cell 112 (second semiconductor light-emittingstructure 112). The light-transmissive substrate 10 has an upper surface10 a forming an upper surface of the light-emitting element 110A, and alower surface 10 b located on the opposite side from the upper surface10 a. As schematically shown in FIG. 4, the first light-emitting cell111 is formed on the lower surface 10 b of the light-transmissivesubstrate 10. Likewise, the second light-emitting cell 112 is alsolocated on the lower surface 10 b of the light-transmissive substrate10. As can be seen from FIG. 3, the first light-emitting cell 111 andthe second light-emitting cell 112 are separated from each other inspace on the lower surface 10 b of the light-transmissive substrate 10,and therefore, are electrically independent of each other.

Each of the first light-emitting cell 111 and the second light-emittingcell 112 may have a structure similar to that of a known semiconductorlight-emitting element such as a light-emitting diode (LED). Here, thefirst light-emitting cell 111 and the second light-emitting cell 112each partially include a structure in which an n-type semiconductorlayer, an active layer, and a p-type semiconductor layer are stacked inthis order with the n-type semiconductor layer closest to thelight-transmissive substrate 10. Here, in a typical embodiment of thepresent disclosure, the plurality of semiconductor light-emittingstructures on the light-transmissive substrate 10 have a common basicconfiguration. Therefore, in the description that follows, of the firstlight-emitting cell 111 and the second light-emitting cell 112,attention is paid to the first light-emitting cell 111, and aconfiguration thereof will be described in detail, and the configurationof the second light-emitting cell 112 will not be described in detail.

The first light-emitting cell 111 has an n-type semiconductor layer 11 non the lower surface 10 b of the light-transmissive substrate 10, and anactive layer 11 e and a p-type semiconductor layer 11 p formed on apartial region of the n-type semiconductor layer 11 n. In other words,the n-type semiconductor layer 11 n of the first light-emitting cell 111has a region Rn that is a portion of the upper surface thereof and isnot covered by either of the active layer 11 e and the p-typesemiconductor layer 11 p. As described above, the first light-emittingcell 111 and the second light-emitting cell 112 are disposed apart fromeach other on the light-transmissive substrate 10, and are therebyelectrically separated from each other. Thus, in the light-emittingelement 110A, the first light-emitting cell 111 and the secondlight-emitting cell 112 are light-emitting structures electricallyindependent of each other. For example, a gap having a width of about 5μm, in which the lower surface 10 b of the light-transmissive substrate10 is exposed, is formed between the first light-emitting cell 111 andthe second light-emitting cell 112.

The active layer of the first light-emitting cell 111 and the activelayer of the second light-emitting cell 112 emit light having a peakwavelength in the range of, for example, 360-650 nm. Theselight-emitting cells may include a nitride semiconductor(In_(x)Al_(y)Ga_(1-x-y)N, 0≤x, 0≤y, and x+y≤1) capable of emitting lighthaving a wavelength in the range from ultraviolet to visible. Note thatif the active layers of the plurality of light-emitting cells (here, thefirst light-emitting cell 111 and the second light-emitting cell 112)have a common shape and area as viewed from above, an extreme luminancedifference is unlikely to occur between each light-emitting cell, whichis advantageous to prevention or reduction of luminance non-uniformity.

The light-transmissive substrate 10 supports the first light-emittingcell 111 and the second light-emitting cell 112. The light-transmissivesubstrate 10 may be an insulating substrate, typified by a sapphiresubstrate and a gallium nitride substrate, for epitaxially growing asemiconductor layer in the formation of the semiconductor multilayerstructure of the first light-emitting cell 111 and the secondlight-emitting cell 112. As used in, the terms “light transmission” and“light-transmissive” are intended to encompass the ability to diffuseincident light, and are not limited to “transparent.” As schematicallyshown in FIG. 4, by providing a minute roughness pattern on the lowersurface 10 b of the light-transmissive substrate 10, the efficiency ofextraction of light from the light-emitting cell can be improved. Theroughness pattern is formed of, for example, a plurality of minuteprotrusions. The protrusions forming the roughness pattern may have aheight of, for example, about 5 nm or more.

The shape of the light-transmissive substrate 10 as viewed from above istypically rectangular, such as square. The sides of the rectangularshape of the light-transmissive substrate 10 have a length in the rangeof, for example, about 300 μm to about 3 mm, preferably in the range of500 μm to 1.5 mm. In FIGS. 1 and 3, the sides of the rectangular shapeof the light-transmissive substrate 10 are parallel to the X directionor the Y direction of the figures.

The light-emitting cells of the light-transmissive substrate 10 eachfurther include one or more insulating layers and electrodes. Forexample, as shown in FIG. 4, the first light-emitting cell 111 furtherhas a first insulating film 13 covering the multilayer structure of then-type semiconductor layer 11 n, the active layer 11 e, and the p-typesemiconductor layer 11 p, an n-internal electrode 15 n and a p-internalelectrode 15 p located on the first insulating film 13, a secondinsulating film 24 covering the n-internal electrode 15 n and thep-internal electrode 15 p, and an n-external electrode 21 n and ap-external electrode 21 p located on the second insulating film 24.

The first insulating film 13, which is formed of an oxide or nitridecontaining one or more selected from the group consisting of Si, Ti, Zr,Nb, Ta, Al, and Hf, continuously covers the first light-emitting cell111 and the second light-emitting cell 112. In particular, SiO₂, whichprovides a high transmittance and a low refractive index for visiblelight, is suitable as a material for the first insulating film 13. Forexample, a multilayer film in which SiO₂ and Nb₂O₅ are alternatelystacked can be suitably used as the first insulating film 13.

A plurality of first through holes 13 t are provided in the firstinsulating film 13. The n-internal electrode 15 n and the p-internalelectrode 15 p described below are electrically coupled to the n-typesemiconductor layer 11 n and the p-type semiconductor layer 11 p,respectively, through the first through holes 13 t. Here, 15 firstthrough holes 13 t are formed in a portion of the first insulating film13 that coincides with or covers the first light-emitting cell 111.First through holes 13 t may be disposed on the region Rn of the n-typesemiconductor layer 11 n of the first light-emitting cell 111. Ofcourse, the number, arrangement, and shapes of the first through holes13 t are not limited to the example of FIG. 3 and may be suitablymodified.

The n-internal electrode 15 n and the p-internal electrode 15 p arelocated on the first insulating film 13, and are electrically coupled tothe n-type semiconductor layer 11 n and the p-type semiconductor layer11 p, respectively. The n-internal electrode 15 n and the p-internalelectrode 15 p are formed of a metal or alloy that has high lightreflectivity and electrical conductivity, such as Al, Ag, an Al alloy,or a Ag alloy. Of these materials, Al and Al alloys, which have highlight reflectivity and is less likely to cause migration compared to Ag,are a material suitable for the n-internal electrode 15 n and thep-internal electrode 15 p. The n-internal electrode 15 n and thep-internal electrode 15 p may be formed of a multilayer film obtained bydepositing Ti, Rh, and Ti in this order.

Note that a light reflective electrode may be provided on the p-typesemiconductor layer 11 p. In that case, the p-internal electrode 15 p iselectrically coupled to the p-type semiconductor layer 11 p through thelight reflective electrode provided on the p-type semiconductor layer 11p. The light reflective electrode may have a shape that coverssubstantially entirely the upper surface of the p-type semiconductorlayer 11 p. The light reflective electrode may be made of a materialsimilar to that for the n-internal electrode 15 n and the p-internalelectrode 15 p. By interposing the light reflective electrode betweenthe p-type semiconductor layer 11 p and the p-internal electrode 15 p, acurrent can be caused to flow in a wider region of the p-typesemiconductor layer 11 p. In addition, light traveling toward theopposite side from the light-transmissive substrate 10 can be reflectedby the light reflective electrode, so that the efficiency of lightextraction can be expected to be improved. It is advantageous to coverthe light reflective electrode with a SiN layer or SiO₂ layer, becausethese layers can serve as a barrier layer that prevents or reducesmigration of a material of the light reflective electrode.

In the case in which the light reflective electrode is disposed on thep-type semiconductor layer 11 p, one or more through holes are alsoprovided in the light reflective electrode. The through hole(s) of thelight reflective electrode are located at a position(s) coinciding withone or more of the first through holes 13 t of the first insulating film13 that are provided on the region Rn of the n-type semiconductor layer11 n. The n-internal electrode 15 n is electrically coupled to then-type semiconductor layer 11 n through the through holes of the lightreflective electrode, and one or more of the first through holes 13 t ofthe first insulating film 13 that are provided on the region Rn of then-type semiconductor layer 11 n.

The second insulating film 24 continuously covers the first insulatingfilm 13, the n-internal electrode 15 n, and the p-internal electrode 15p. The second insulating film 24 has a second through hole 24 tn at aposition coinciding with the n-internal electrode 15 n. The n-externalelectrode 21 n described below is electrically coupled to the n-internalelectrode 15 n through the second through hole 24 tn. The secondinsulating film 24 also has a third through hole 24 tp at a positioncoinciding with the p-internal electrode 15 p. The p-external electrode21 p described below is electrically coupled to the p-internal electrode15 p through the third through hole 24 tp. In this example, each of thefirst light-emitting cell 111 and the second light-emitting cell 112 hasa single second through hole 24 tn and a single third through hole 24tp. Of course, the numbers, arrangements, and shapes of second throughholes 24 tn and third through holes 24 tp are not limited to those ofthe example of FIG. 3 and may be suitably modified.

The second insulating film 24 may be formed of the same material as thatfor the first insulating film 13, such as SiO₂. The materials for thesecond insulating film 24 and the first insulating film 13 may be thesame or different. If a material having a refractive index lower thanthose of a material for the light-emitting cell and a material for thelight-transmissive substrate 10 and having a large refractive indexdifference from those of these materials, is used as a material for thesecond insulating film 24 and/or the first insulating film 13, leakageof light from the opposite side from the light-transmissive substrate 10is prevented or reduced, so that the effect of improving the efficiencyof light extraction can be expected.

As schematically shown in FIG. 4, the n-external electrode 21 n islocated on the second insulating film 24, and is electrically coupled tothe n-internal electrode 15 n through the second through hole 24 tn ofthe second insulating film 24. Likewise, the p-external electrode 21 pis located on the second insulating film 24, and is electrically coupledto the p-internal electrode 15 p through the third through hole 24 tp ofthe second insulating film 24. Thus, the n-external electrode 21 n iselectrically coupled to the n-type semiconductor layer 11 n of the firstlight-emitting cell 111, and the p-external electrode 21 p iselectrically coupled to the p-type semiconductor layer 11 p of the firstlight-emitting cell 111. Thus, the n-external electrode 21 n and thep-external electrode 21 p serve as a pad electrode for supplying apredetermined current to the semiconductor layer in the firstlight-emitting cell 111.

As shown in FIG. 3, the second light-emitting cell 112 also has, on theopposite side from the upper surface of the light-emitting element 110A,i.e., the upper surface 10 a of the light-transmissive substrate 10, ann-external electrode 22 n electrically coupled to the n-typesemiconductor layer of the second light-emitting cell 112, and ap-external electrode 22 p electrically coupled to the p-typesemiconductor layer of the second light-emitting cell 112. Thus, thelight-emitting element 110A has the first light-emitting cell 111 andthe second light-emitting cell 112, which are configured to be able tobe driven independently of each other when coupled to a power supply,etc.

The n-external electrode 21 n and the p-external electrode 21 p of thefirst light-emitting cell 111, and the n-external electrode 22 n and thep-external electrode 22 p of the second light-emitting cell 112, may beformed of, for example, plating, and may have a multilayer structure oftwo or more layers including a first layer as a seed layer and a secondlayer on the first layer. As a material for the first layer, a metal oralloy that has high light reflectivity and electrical conductivity, suchas Al, Ag, an Al alloy, or a Ag alloy, can be used. Examples of atypical material for the second layer include Cu, Au, and Ni. As then-external electrode 21 n, the p-external electrode 21 p, the n-externalelectrode 22 n, and the p-external electrode 22 p, a multilayer film maybe used in which Ti, Ni, and Al are deposited in this order with the Tilayer closet to the light-transmissive substrate 10.

The lower surfaces of the first light-emitting cell 111 and thep-external electrode 21 p of the n-external electrode 21 n, and thelower surfaces of the n-external electrode 22 n and the p-externalelectrode 22 p of the second light-emitting cell 112, are located atsubstantially the same height with respect to the lower surface 10 b ofthe light-transmissive substrate 10. Each of the n-external electrode 21n, the p-external electrode 21 p, the n-external electrode 22 n, and thep-external electrode 22 p may have a dimension of about 150-200 μm asviewed from above. If the uppermost surface layers of these padelectrodes are a Au layer, eutectic bonding is advantageously applicableto bonding of the pad electrodes to the interconnection layer 153A ofthe substrate 150. The n-external electrode 21 n, the p-externalelectrode 21 p, the n-external electrode 22 n, and the p-externalelectrode 22 p are disposed and shaped at a position not coinciding withthe first through hole 13 t provided in the first insulating film 13,whereby the occurrence of a crack in the first insulating film 13 or thesecond insulating film 24 due to thermal stress during eutectic bondingcan be prevented or reduced.

Note that, in this example, the second light-emitting cell 112 has aconfiguration similar to that of a structure obtained by turning thefirst light-emitting cell 111 around the light-emitting element 110A by180° as viewed from above. Therefore, in the example of FIG. 3, thep-external electrode 21 p of the first light-emitting cell 111 and then-external electrode 22 n of the second light-emitting cell 112 arearranged horizontally side by side in the drawing sheet of FIG. 3, andthe n-external electrode 21 n of the first light-emitting cell 111 andthe p-external electrode 22 p of the second light-emitting cell 112 arearranged horizontally side by side in the drawing sheet of FIG. 3.

[Substrate 150]

Reference is made back to FIGS. 1 and 2. The substrate 150, which islocated on the opposite side from the light-transmissive substrate 10 ofthe light-emitting element 110A, supports the light-emitting element110A. The substrate 150, which is formed of an insulating material suchas a resin or ceramic, has the interconnection layer 153A, and the firstreflective member 154 covering a portion of the interconnection layer153A, on the upper surface 150 a closer to the light-emitting element110A. Examples of a material for the body portion of the substrate 150,excluding the interconnection layer 153A and the first reflective member154, include resins such as phenolic resins, epoxy resins, polyimideresins, bismaleimide triazine resins (BT resins), polyphthalamides(PPAs), polyethylene terephthalate (PET), and polyethylene naphthalate(PEN), and ceramics such as alumina, mullite, forsterite, glassceramics, nitride ceramics (e.g., AlN), carbide ceramics (e.g., SiC),and low temperature co-fired ceramics (LTCCs). The body portion of thesubstrate 150 may be formed of a composite material, which may beobtained by, for example, mixing the above resin with an inorganicfiller such as glass fibers, SiO₂, TiO₂, or Al₂O₃.

The interconnection layer 153A, which is located between the bodyportion of the substrate 150 and the first reflective member 154, hasthe function of supplying a predetermined current to the light-emittingelement 110A of the substrate 150 when coupled to an external drivecircuit or the like. The interconnection layer 153A may be a metal layerof Cu, Ni, or the like formed by adhesion caused by plating, sputtering,vapor deposition, or pressing. In the case in which, for example, aceramic is used as a material for the body portion of the substrate 150,a high-melting-point metal that can be co-fired with the ceramic of thebody portion of the substrate 150, such as W or Mo, can be used as amaterial for the interconnection layer 153A. The interconnection layer153A may have a multilayer structure. For example, the interconnectionlayer 153A may have a pattern of the high-melting-point metal formed bythe above method, and a layer containing another metal such as Ni, Au,or Ag which is formed by plating, sputtering, vapor deposition, or thelike.

As described above, the interconnection layer 153A has the firstinterconnection portion 31, the second interconnection portion 32, andthe third interconnection portion 33. The first interconnection portion31 has the first land L1. The second interconnection portion 32 has thesecond land L2 and the third land L3 electrically coupled to each otherthrough the connection portion 30. The third interconnection portion 33has the fourth land L4. The n-external electrode 21 n of the firstlight-emitting cell 111 described above with reference to FIG. 3 iscoupled to the first land L1 of the first interconnection portion 31.Meanwhile, the p-external electrode 21 p of the first light-emittingcell 111 is coupled to the second land L2 of the second interconnectionportion 32. The n-external electrode 22 n and the p-external electrode22 p of the second light-emitting cell 112 of FIG. 3 is coupled to thethird land L3 of the second interconnection portion 32 and the fourthland L4 of the third interconnection portion 33, respectively. FIG. 1shows a state in which the light-emitting element 110A is mounted on thesubstrate 150. A bonding member such as Au—Sn solder or Ag—Sn solder canbe used to provide coupling between the n-external electrode 21 n andthe first land L1, between the p-external electrode 21 p and the secondland L2, between the n-external electrode 22 n and the third land L3,and between the p-external electrode 22 p and the fourth land L4.

FIG. 5 shows an equivalent circuit of the light-emitting device 100Aincluding the light-emitting element 110A mounted on the substrate 150.As shown in FIG. 5, the p-external electrode 21 p of the firstlight-emitting cell 111 is coupled to the second land L2 of the secondinterconnection portion 32, and the n-external electrode 22 n of thesecond light-emitting cell 112 is coupled to the third land L3 of thesecond interconnection portion 32, so that the first light-emitting cell111 and the second light-emitting cell 112, which are electricallyindependent of each other in the light-emitting element 110A, areelectrically coupled together in series through the secondinterconnection portion 32 of the interconnection layer 153A.

Here, referring to FIG. 1, each of the first land L1, the second landL2, the third land L3, and the fourth land L4 has a portion exposed inthe opening 154 z of the insulating first reflective member 154.Therefore, by selecting two appropriate ones of these lands and, forexample, causing a current to pass through the selected lands, a voltagedrop occurring when a reverse voltage is applied (or a forward voltageis applied) can be measured for one of the first light-emitting cell 111and the second light-emitting cell 112. Thus, the first light-emittingcell 111 and the second light-emitting cell 112 can be inspected for adefect such as leakage current even with the first light-emitting cell111 and the second light-emitting cell 112 coupled together in series.

Note that the distance between the n-external electrode 21 n and thep-external electrode 21 p of the first light-emitting cell 111, and thedistance between the n-external electrode 22 n and the p-externalelectrode 22 p of the second light-emitting cell 112, are no greaterthan about several hundreds of micrometers. On the other hand, in theembodiment of the present disclosure, the light-emitting element 110Ahas already been mounted on the substrate 150, and therefore, a voltagedrop, etc., can be easily measured, because two appropriate ones can beselected from the first land L1, the second land L2, the third land L3,and the fourth land L4 by comparing the areas of the positive andnegative electrodes provided in each light-emitting cell, and ameasurement probe can be brought into contact with the selected lands.In addition, the first land L1, the second land L2, the third land L3,and the fourth land L4 can have a large region that is exposed in theopening 154 z of the first reflective member 154 and does not overlapthe light-emitting element 110A. Therefore, a measurement probe, etc.,can be easily brought into contact with the first land L1, the secondland L2, the third land L3, and the fourth land L4, and therefore, it iseasier to perform an inspection for a defect such as leakage current.

The first reflective member 154, which is formed of, for example, aresin material in which a light reflective filler is dispersed, has areflectance of 60% or more with respect to the peak wavelength of lightemitted by the light-emitting element 110A. The first reflective member154 may also have the function of preventing or reducing excessivespread of a bonding member on the interconnection layer 153A, as asolder resist. The first reflective member 154 more advantageously has areflectance of 70% or more, even more advantageously 80% or more, withrespect to the peak wavelength of light emitted by the light-emittingelement 110A.

In the example of FIG. 1, most of the interconnection layer 153A iscovered by the first reflective member 154. Therefore, a portion oflight emitted from the light-emitting element 110A that travels towardthe substrate 150 can be efficiently reflected by the first reflectivemember 154 toward the opposite side from the substrate 150. In thisexample, the opening 154 z of the first reflective member 154 has anoctagonal shape symmetrical about the center of the light-emittingelement 110A as viewed from above. The portions of the first land L1,the second land L2, the third land L3, and the fourth land L4 of theinterconnection layer 153A that are exposed in the opening 154 z of thefirst reflective member 154 has a 4-fold rotational symmetricalarrangement about the center of the light-emitting element 110A.

By arranging the lands of the interconnection layer 153A, which absorbslight more easily than the first reflective member 154, in a rotationalsymmetry (here, 4-fold rotational symmetry) about the center of thelight-emitting element 110A, the anisotropy of light absorption by theinterconnection layer 153A can be reduced. Thus, non-uniform lightdistribution in the XY plane of the figure is prevented or reduced, andthereby, more uniform light distribution can be achieved. In particular,in this example, a slit-shaped gap G20 is also provided between thesecond land L2 and the third land L3 of the second interconnectionportion 32, so that the gap G20 is extended inside the opening 154 z ofthe first reflective member 154. In addition, the connection portion 30coupling the second land L2 and the third land L3 of the secondinterconnection portion 32 together is entirely covered by the firstreflective member 154. Such a configuration makes it easier to introducesymmetry into the shape and arrangement of a plurality of portions ofthe interconnection layer 153A that are exposed in the opening 154 z ofthe first reflective member 154. In addition, inside the opening 154 zof the first reflective member 154, the gaps G12, G20, G23, and G31extend in four symmetrical directions, and therefore, the tilt of thelight-emitting element 110A that would occur due to the large or smallamount of the bonding member can be advantageously easily avoided orreduced. The shape of the opening 154 z of the first reflective member154 is not limited to the octagonal shape of FIG. 1, and may becircular, quadrilateral, etc.

Examples of a base material of a resin material for forming the firstreflective member 154 include silicone resins, phenolic resins, epoxyresins, BT resins, and polyphthalamides (PPAs). As the light reflectivefiller, metal particles, or particles of an inorganic or organicmaterial that has a refractive index higher than that of the basematerial in which the light reflective filler is dispersed, can be used.Examples of the light reflective filler include particles of titaniumdioxide, silicon oxide, zirconium dioxide, potassium titanate, aluminumoxide, aluminum nitride, boron nitride, mullite, niobium oxide, orbarium sulfate, or particles of various rare-earth oxides, such asyttrium oxide and gadolinium oxide. The first reflective member 154advantageously has a white color.

[Light-Transmissive Member 160]

In the configuration illustrated in FIGS. 1 and 2, the light-emittingdevice 100A has the light-transmissive member 160 covering the entirelight-emitting element 110A and a portion of the first reflective member154. The light-transmissive member 160 protects the light-emittingelement 110A from external force, dust, water, etc., and may serve as alens for adjusting distribution of light emitted by the light-emittingelement 110A.

In the example of FIG. 2, the light-transmissive member 160 has a recessin a portion thereof directly above the light-emitting element 110A.Therefore, in this example, a peak portion 160 t of thelight-transmissive member 160 that is a highest portion (a portionfurthest from the upper surface 150 a of the substrate 150) is in theshape of a circular ring whose center coincides with the light-emittingelement 110A as viewed from above. Such a shape of thelight-transmissive member 160 easily prevents or reduces an extremeincrease in luminance at a portion directly above the light-emittingelement 110A.

The light-transmissive member 160 has the recess 160 r on a side thereofcloser to the substrate 150. The light-emitting element 110A is disposedin the recess 160 r. The recess 160 r is in the shape of, for example, atruncated cone in which the bottom portion of the recess (the uppersurface of the truncated cone) is smaller than the opening of the recess(the base of the truncated cone). The recess 160 r is disposed so thatthe emission surface of the light-emitting element 110A is opposite thebottom portion of the recess 160 r. The shape of the recess 160 r is notlimited to the truncated cone, and may be a truncated pyramid in whichthe opening and bottom portion of the recess are quadrilateral. In theexample of FIG. 1, the light-transmissive member 160 is supported by thesubstrate 150.

As a material for the light-transmissive member 160, a resin materialcontaining a transparent resin or the like as a base material can beused. A typical example of the base material for the light-transmissivemember 160 is a thermosetting resin, such as an epoxy resin or siliconeresin. As the base material for the light-transmissive member 160, asilicone resin, silicone modified resin, epoxy resin, phenolic resin,polycarbonate resin, acrylic resin, polymethyl pentene resin, orpolynorbornene resin, or a material containing two or more suchmaterials, may be used. By dispersing a material having a refractiveindex different from that of the base material in the material of thelight-transmissive member 160, a light diffusion function may beimparted to the light-transmissive member 160. For example, particles oftitanium dioxide, silicon oxide, or the like may be dispersed in thebase material of the light-transmissive member 160. Alternatively, awavelength conversion function may be imparted by dispersing particlesof a fluorescent material in the base material of the light-transmissivemember 160.

In the configuration illustrated in FIG. 2, an underfill 162 is disposedbetween the light-emitting element 110A and the upper surface 150 a ofthe substrate 150. The underfill 162 may be disposed in the recess 160 rof the light-transmissive member 160 so as to cover a lateral surface ofthe light-emitting element 110A. After the light-emitting element 110Ais mounted on the substrate 150, the underfill 162 may be formed beforethe light-transmissive member 160 is formed. Here, the underfill 162advantageously has a refractive index lower than that of thelight-transmissive member 160. If the underfill 162 and thelight-transmissive member 160 have such a refractive index relationship,light emitted from the lateral surface of the light-emitting element110A is refracted by an interface between the underfill 162 and thelight-transmissive member 160, so that the light emitted from thelateral surface of the light-emitting element 110A can be extracted in adirection oblique to the normal direction of the substrate 150. Inaddition, if the light-transmissive member 160 is formed of a materialhaving higher thixotropy that that of the material for the underfill162, the lateral surface of the light-emitting element 110A can beeasily covered by the underfill 162, and the light-transmissive member160 having a desired external shape can be formed with high precision.As an example of such a material combination, the underfill 162 may beformed of dimethyl silicone, and the light-transmissive member 160 maybe formed of phenyl silicone.

(Variations)

FIG. 6 shows a variation of the light-emitting device of the embodimentof the present disclosure. Compared to the light-emitting device 100A ofFIG. 2, a light-emitting device 100B shown in FIG. 6 has alight-emitting element 110B instead of the light-emitting element 110A.The light-emitting element 110A and the light-emitting element 110B havea common feature that each of them has the first light-emitting cell 111and the second light-emitting cell 112.

In the example of FIG. 6, the light-emitting element 110B has areflective layer 40 on the upper surface 10 a of the light-transmissivesubstrate 10. The reflective layer 40 is, for example, a metal film ordielectric multilayer film. An example material for the dielectricmultilayer film is an oxide or nitride containing at least one selectedfrom the group consisting of Si, Ti, Zr, Nb, Ta, Al, and Hf. Forexample, a multilayer film in which SiO₂ and Nb₂O₅ are alternatelystacked can be used as the reflective layer 40. If the reflective layer40 is provided on the upper surface of the light-emitting element 110B,the emission of light from the upper surface 10 a of thelight-transmissive substrate 10 can be prevented or reduced, so thatbatwing light distribution characteristics can be more easily obtained.As used herein, the term “batwing light distribution characteristics”refers to light distribution characteristics that are defined as anemission intensity distribution in which the emission intensity ishigher at light distribution angles whose absolute values are greaterthan zero, where the optical axis has a light distribution angle of 0°.The disposition of the reflective layer 40 on the upper surface of thelight-emitting element 110B contributes to the reduction of thethickness of the light-emitting device 100B.

FIG. 7 shows another variation of the light-emitting device of theembodiment of the present disclosure. Compared to the light-emittingdevice 100A, of FIG. 2, a light-emitting device 100C shown in FIG. 7 hasa light-emitting element 110C instead of the light-emitting element110A. The light-emitting element 110A and the light-emitting element110C have a common feature that each of them has the firstlight-emitting cell 111 and the second light-emitting cell 112. Thelight-emitting element 110C includes the first light-emitting cell 111and the second light-emitting cell 112, a light-transmissive substrate10 disposed on the first light-emitting cell 111 and the secondlight-emitting cell 112, a wavelength conversion member 51 located onthe light-transmissive substrate 10, and a diffusion member 52 locatedon the wavelength conversion member 51. The wavelength conversion member51 is bonded to the light-transmissive substrate 10 through a bondingmember 53. The wavelength conversion member 51 is bonded to thediffusion member 52.

The wavelength conversion member 51 absorbs at least a portion of lightemitted from the first light-emitting cell 111 and the secondlight-emitting cell 112, and emits light having a wavelength differentfrom that of light emitted by the first light-emitting cell 111 and thesecond light-emitting cell 112. For example, the wavelength conversionmember 51 performs wavelength conversion on a portion of blue lightemitted by the first light-emitting cell 111 and the secondlight-emitting cell 112, and thereby emits yellow light. By such aconfiguration, blue light transmitted through the wavelength conversionmember 51 and yellow light emitted by the wavelength conversion member51 are mixed together to provide white light.

The wavelength conversion member 51 is typically a member in whichparticles of a fluorescent material are dispersed in a resin. As theresin in which particles of a fluorescent material or the like aredispersed, a silicone resin, modified silicone resin, epoxy resin,modified epoxy resin, urea resin, phenolic resin, acrylic resin,urethane resin, or fluoropolymer, or a resin containing two or more suchmaterials, can be used. A material having a refractive index differentfrom that of the base material may be dispersed in the material of thewavelength conversion member 51 to impart a light diffusion function tothe wavelength conversion member 51. For example, particles of titaniumdioxide, silicon oxide, or the like may be dispersed in the basematerial of the wavelength conversion member 51.

As the fluorescent material, a known material can be used. Examples ofthe fluorescent material include fluoride fluorescent materials, such asYAG fluorescent materials and KSF fluorescent materials, nitridefluorescent materials, such as CASN, and β-SiAlON fluorescent materials.YAG fluorescent materials are examples of wavelength conversionsubstances that convert blue light into yellow light. KSF fluorescentmaterials and CASN are examples of wavelength conversion substances thatconvert blue light into red light. β-SiAlON fluorescent materials areexamples of wavelength conversion substances that convert blue lightinto green light. The fluorescent material may be a quantumdot-fluorescent material.

As a material for the bonding member 53, a resin composition containinga transparent resin material as a base material can be used. A typicalexample of the base material for the bonding member 53 is athermosetting resin, such as an epoxy resin or silicone resin. As thebase material for the bonding member 53, a silicone resin, siliconemodified resin, epoxy resin, phenolic resin, polycarbonate resin,acrylic resin, polymethyl pentene resin, or polynorbornene resin, or amaterial containing two or more such materials, may be used. Forexample, a material having a refractive index different from that of thebase material for the bonding member 53 may be dispersed in the basematerial so that a light diffusion function is imparted to the bondingmember 53.

The diffusion member 52 diffuses and transmits incident light from thewavelength conversion member 51. The diffusion member 52 is formed of,for example, a material that does not absorb much visible light, such asa polycarbonate resin, polystyrene resin, acrylic resin, or polyethyleneresin. A structure for diffusing light is provided in the diffusionmember 52 by providing roughness on a surface of the diffusion member52, or dispersing a material having a different refractive index in thediffusion member 52. As the diffusion member 52, a commerciallyavailable diffusion member called a “light diffusion sheet,” “diffuserfilm,” or the like may be used.

The light-emitting element 110C preferably includes a light reflectivemember 54 that covers lateral surfaces of the first light-emitting cell111, the second light-emitting cell 112, the light-transmissivesubstrate 10, the wavelength conversion member 51, and the diffusionmember 52. In that case, the diffusion member 52 is preferably exposedon an upper surface 54 a of the light reflective member 54, andelectrodes 55 of the first light-emitting cell 111 and the secondlight-emitting cell 112 are preferably exposed on the lower surface 54 bof the light reflective member 54. In addition, in that case, mountingelectrodes 56 that cover the electrodes 55 are preferably on the lowersurface 54 b of the light reflective member 54. The lower surface 54 bis larger than the electrodes 55 of the first light-emitting cell 111and the second light-emitting cell 112, and therefore, the electrodes 56can have a larger area. Therefore, when the light-emitting device 100Cis mounted on the substrate 150, the area of contact of a bonding membersuch as solder with the substrate 150 can be increased, resulting ineasier mounting and greater bonding strength. The light-emitting element110C having such a structure is also called a “direct mountable chip.”

The light-emitting element 110C is disposed in the recess 160 r of thelight-transmissive member 160. Specifically, the upper surface 54 a ofthe light reflective member 54 is bonded to the light-transmissivemember 160 by a light-transmissive bonding member 58 or the like so asto be opposite to the bottom portion of the recess 160 r. The bondingmember 58 may be in the shape of a fillet and may cover a portion of thelateral surface of the light-transmissive member 160. A height of thelight-emitting element 110C is greater than a depth of the recess 160 r.Therefore, the light-transmissive member 160 is supported by thelight-emitting element 110C, so that a lower surface 160 b of thelight-transmissive member 160 is not in contact with, i.e., is apartfrom, the substrate 150, and the first reflective member 154 disposed onthe substrate 150. After the light-emitting element 110C is produced,the light-emitting element 110C can be bonded to the recess 160 r of thelight-transmissive member 160 by a bonding member or the like to producethe light-emitting device 100C. With such a structure, for example, inthe stage that the light-emitting device 100C has been produced, if theoptical axes of the light-emitting element 110C and thelight-transmissive member 160 are not coaxial, that light-emittingdevice 100C is considered out of specification and can be discarded.Therefore, when the light-emitting device 100C is mounted on thesubstrate 150, it is not necessary to position the light-emittingelement 110C and the light-transmissive member 160 relative to eachother. Therefore, compared to the case in which the light-emittingelement 110C and the light-transmissive member 160 are disposed on thesubstrate 150, the occurrence of a defective product caused by anunacceptable positioning error can be prevented or reduced.

FIG. 8 shows another variation of the light-emitting device of theembodiment of the present disclosure. Compared to the light-emittingdevice 100A of FIG. 1, a light-emitting device 100D shown in FIG. 8 hasa light-emitting element 110D and an interconnection layer 153B insteadof the light-emitting element 110A and the interconnection layer 153A.

The light-emitting element 110D of the light-emitting device 100D has athird light-emitting cell 113 having a third semiconductorlight-emitting structure in addition to the first light-emitting cell111 and the second light-emitting cell 112. The third light-emittingcell 113 has substantially the same structure as that of the firstlight-emitting cell 111. For example, as with the first light-emittingcell 111, the third light-emitting cell 113 is located on the lowersurface 10 b of the light-transmissive substrate 10. In addition, thethird light-emitting cell 113 has an n-external electrode 23 n (firstelectrode) electrically coupled to an n-type semiconductor layer of thethird light-emitting cell 113, and a p-external electrode 23 p (secondelectrode) electrically coupled to a p-type semiconductor layer of thethird light-emitting cell 113, on the opposite side from thelight-transmissive substrate 10.

In the configuration illustrated in FIG. 8, the interconnection layer153B has a first interconnection portion 31 including a first land L1, asecond interconnection portion 32 including a second land L2 and a thirdland L3, and a third interconnection portion 33 including a fourth landL4. Here, the third interconnection portion 33 of the interconnectionlayer 153B further includes a connection portion 39 and a fifth land L5.The fifth land L5 is electrically coupled to the fourth land L4 throughthe connection portion 39. The interconnection layer 153B further has afourth interconnection portion 34 including a sixth land L6 as a portionthereof in addition to the first interconnection portion 31, the secondinterconnection portion 32, and the third interconnection portion 33. Asshown in FIG. 8, a portion of the fifth land L5 of the thirdinterconnection portion 33 and a portion of the sixth land L6 of thefourth interconnection portion 34 are exposed inside the opening 154 zof the first reflective member 154, as with a portion of each of theother lands. Meanwhile, the entire connection portion 39 of the thirdinterconnection portion 33 is located under the first reflective member154, and therefore, is covered by the first reflective member 154.

Also in the light-emitting device 100D, a first electrode (e.g., ann-external electrode 21 n) of the first light-emitting cell 111 iscoupled to the first land L1 of the first interconnection portion 31inside the opening 154 z, and a second electrode (e.g., a p-externalelectrode 21 p) of the first light-emitting cell 111 is coupled to thesecond land L2 of the second interconnection portion 32 inside theopening 154 z, which is similar to each example described above. Inaddition, a first electrode (e.g., an n-external electrode 22 n) of thesecond light-emitting cell 112 is coupled to the third land L3 of thesecond interconnection portion 32 inside the opening 154 z, and a secondelectrode (e.g., a p-external electrode 22 p) of the secondlight-emitting cell 112 is coupled to the fourth land L4 of the thirdinterconnection portion 33 inside the opening 154 z, which is alsosimilar to each example described above.

In this example, the n-external electrode 23 n of the thirdlight-emitting cell 113 as the first electrode is coupled to a portionof the fifth land L5 of the third interconnection portion 33 that isexposed inside the opening 154 z. In addition, the p-external electrode23 p of the third light-emitting cell 113 as the second electrode iscoupled to a portion of the sixth land L6 of the fourth interconnectionportion 34 that is exposed inside the opening 154 z. As described above,the fourth land L4 and the fifth land L5 are electrically coupled toeach other through the connection portion 39, so that the firstlight-emitting cell 111, the second light-emitting cell 112, and thethird light-emitting cell 113 in the light-emitting element 110C areelectrically coupled together in series through the interconnectionlayer 153B.

As in each example described above, in this example, the electrodes ofeach light-emitting cell in the light-emitting element 110C are coupledto the respective corresponding lands of the interconnection layer 153B,and a portion of each land of the interconnection layer 153B is exposedinside the opening 154 z of the first reflective member 154. Therefore,for example, if a probe is selectively brought into contact with thefifth land L5 of the third interconnection portion 33 and the sixth landL6 of the fourth interconnection portion 34, electrical characteristicsof the third light-emitting cell 113 of the plurality of light-emittingcells in the light-emitting element 110C can be selectively measured. Inaddition, as in each example described above, if the first land L1 ofthe first interconnection portion 31 and the second land L2 of thesecond interconnection portion 32 are selected, electricalcharacteristics of the first light-emitting cell 111 can be measured,and if the third land L3 of the second interconnection portion 32 andthe fourth land L4 of the third interconnection portion 33 are selected,electrical characteristics of the second light-emitting cell 112 can bemeasured.

Thus, with the configuration illustrated in FIG. 8, electricalcharacteristics of each of the first light-emitting cell 111, the secondlight-emitting cell 112, and the third light-emitting cell 113 includedin the light-emitting element 110D can be measured individually evenwith these cells electrically coupled together in series. Therefore, thefirst light-emitting cell 111, the second light-emitting cell 112, andthe third light-emitting cell 113 can be inspected for the presence orabsence of a defect such as leakage current for each light-emittingcell, i.e., the presence or absence of a defect can be detected on acell-by-cell basis.

The arrangement of a plurality of electrodes included in alight-emitting element and the land pattern of an interconnection layerare not limited to the examples of FIGS. 1 and 8, and can be changed asappropriate. FIG. 9 shows another variation of the light-emitting deviceof the embodiment of the present disclosure. A main difference between alight-emitting device 100E shown in FIG. 9 and the light-emitting device100D of FIG. 8 is that the light-emitting device 100E has alight-emitting element 110E and an interconnection layer 153C instead ofthe light-emitting element 110D and the interconnection layer 153B.

As with the light-emitting element 110D of FIG. 8, the light-emittingelement 110E in the light-emitting device 100E includes a firstlight-emitting cell 111, a second light-emitting cell 112, and a thirdlight-emitting cell 113, each of which has a first and a secondelectrode. Note that the disposition of the first light-emitting cell111, the second light-emitting cell 112, and the third light-emittingcell 113 in the light-emitting element 110E is different from that inthe light-emitting element 110D of FIG. 8.

In the configuration illustrated in FIG. 9, coupling between theelectrodes of the light-emitting cells and the lands of theinterconnection layer is similar to that of the example described withreference to FIG. 8. Specifically, the first electrode (e.g., ann-external electrode 21 n) and the second electrode (e.g., a p-externalelectrode 21 p) of the first light-emitting cell 111 are coupled to afirst land L1 of a first interconnection portion 31 and a second land L2of a second interconnection portion 32, respectively. The firstelectrode (e.g., an n-external electrode 22 n) and the second electrode(e.g., a p-external electrode 22 p) of the second light-emitting cell112 are coupled to a third land L3 of the second interconnection portion32 and a fourth land L4 of a third interconnection portion 33,respectively. The first electrode (here, an n-external electrode 23 n)and the second electrode (here, a p-external electrode 23 p) of thethird light-emitting cell 113 are coupled to a fifth land L5 of thethird interconnection portion 33 and a sixth land L6 of a fourthinterconnection portion 34, respectively.

Thus, an interconnection layer having a shape corresponding to thedisposition of electrodes included in a plurality of light-emittingcells in a light-emitting element is provided on the substrate 150,whereby even if the number of light-emitting cells included in thelight-emitting element is three or more, the presence or absence of adefect related to each light-emitting cell can be investigated with thelight-emitting cells coupled together in series. Furthermore, in theexamples of FIGS. 8 and 9, portions of the fourth land L4 and the fifthland L5 of the third interconnection portion 33 that are exposed in theopening 154 z of the first reflective member 154 are separated from eachother in space. Such a land pattern can prevent or reduce thenon-uniformity of the areas inside the opening 154 z of theinterconnection layer 153C formed of a material that typically easilyabsorbs light emitted by the light-emitting element compared to thefirst reflective member 154. Therefore, the uniformity of lightdistribution in the XY plane can be improved. Note that thelight-emitting element 110E and the light-emitting element 110Ddescribed above with reference to FIG. 8 may have a reflective layer 40on an upper side thereof (e.g., the upper surface 10 a of thelight-transmissive substrate 10) as with the light-emitting element110B.

FIG. 10 shows another variation of the light-emitting device of theembodiment of the present disclosure. In a light-emitting device 100Fshown in FIG. 10, the gap provided between two adjacent lands of theinterconnection layer 153A has a different shape compared to thelight-emitting device 100A of FIG. 1, etc. Specifically, as to twoadjacent ones of the first land L1, the second land L2, the third landL3, and the fourth land L4 of the interconnection layer 153A, a distanceGL4 between two adjacent lands located in the opening 154 z of the firstreflective member 154 as viewed from above and in a region outside thelight-emitting element 110A, is greater than a distance GL3 between thetwo adjacent lands located under the light-emitting element 110A. In theexample of FIG. 10, the above structure is provided for all of the fourgaps G12, G20, G23, and G31. The present disclosure is not limited tothis example. The above structure may be provided in at least one gap,i.e., between at least one pair of two adjacent lands.

In the case in which the substrate 150 is formed of a white-colormaterial, etc., and the interconnection layer 153A is formed of Cu,etc., the reflectance of the upper surface 150 a of the substrate 150 ishigher than that of the surfaces of the first land L1, the second landL2, the third land L3, and the fourth land L4 of the interconnectionlayer 153A. Therefore, the above structure of the light-emitting device100E can provide a larger area in which the upper surface 150 a of thesubstrate 150 is exposed in the opening 154 z of the first reflectivemember 154. This allows light emitted from the light-emitting element110A, toward the substrate 150 to be efficiently reflected upward,resulting in an increase in the efficiency of light extraction. Inaddition, in the region under the light-emitting element 110A, thedistance GL3 between two adjacent lands can be relatively decreased.Therefore, even in the case in which the space between electrodes of thelight-emitting element 110A, is small, the light-emitting element 110A,can be coupled to the interconnection layer 153A without using aninterposer or the like.

As shown in FIG. 10, in the gaps G12, G20, G23, and G31 between twoadjacent lands, a curved portion GR having a rounded angle may beprovided at or near a boundary between the region of the distance GL3and the region of the distance GL4. As viewed from above, the curvedportion GR protrudes toward the land, e.g., is convex toward the land.In the case in which the gaps G12, G20, G23, and G31 have the curvedportion GR, when the light-emitting element 110A, is bonded to the land,the overflow of an excess of solder, etc., from the interconnectionlayer 153A at or near the boundary between the region of the distanceGL3 and the region of the distance GL4 can be prevented or reduced, andtherefore, the solder can be smoothly spread on the interconnectionlayer 153A.

FIG. 11 shows another variation of the light-emitting device of theembodiment of the present disclosure. In a light-emitting device 100Gshown in FIG. 11, like the light-emitting device 100E, a gap providedbetween two adjacent lands of the interconnection layer 153A has adifferent shape compared to the light-emitting device 100A of FIG. 1,etc. In the light-emitting device 100G, a distance between two adjacentlands in the opening 154 z of the first reflective member 154 as viewedfrom above and in a region outside the light-emitting element 110A,becomes greater stepwise or continuously from a side closer to thelight-emitting element to a side further from the light-emittingelement. As shown in FIG. 11, a distance GL5 is located further from thelight-emitting element 110A than is a distance GL4, and the distance GL5is greater than the distance GL4. GL4 and GL5 are each greater than adistance GL3 in a region under the light-emitting element 110A. In theexample of FIG. 11, the distance between two adjacent lands in theopening 154 z of the first reflective member 154 and in a region outsidethe light-emitting element 110A, becomes greater continuously in adirection away from the light-emitting element 110A. However, thedistance between two adjacent lands may become greater stepwise in adirection away from the light-emitting element 110A.

FIG. 12 shows still another variation of the light-emitting device ofthe embodiment of the present disclosure. In a light-emitting device100H shown in FIG. 12, like the light-emitting device 100G of FIG. 11,the gap provided between two adjacent lands of the interconnection layer153A has a different shape compared to the light-emitting device 100A ofFIG. 1, etc. In the light-emitting device 100H, as viewed from above,the distance between two lands is greater in a region R1 that is outsidethe opening 154 z of the first reflective member 154 and is adjacent tothe opening 154 z than in the opening 154 z of the first reflectivemember 154. In addition, the distance between two lands is smaller in aregion R2 that is further than the region R1 from the light-emittingelement 110A, than in the region R1.

As shown in FIG. 12, in the case in which the distances between twolands in the opening 154 z of the first reflective member 154, theregion R1, and the region R2 are represented by GL5, GL6, and GL7,respectively, GL5<GL6 and GL6>GL7 are satisfied. In the region R1, thedistance GL6 between two lands may become greater stepwise orcontinuously in a direction away from the light-emitting element 110A.Alternatively, the distance GL6 between two lands may be invariable inthe region R1, provided that GL5<GL6.

If GL5<GL6 is satisfied, the area of the exposed surface of thesubstrate 150 is relatively larger than the land under the firstreflective member 154 located in the region R1. Therefore, if thematerial for the substrate 150 has a reflectance higher than that of thematerial for the interconnection layer 153A, the absorption of lightfrom the light-emitting element 110A by the first reflective member 154located in the region R1 can be prevented or reduced. In addition, ifGL6>GL7 is satisfied, the land has a larger area. Therefore, heatdissipation properties of the region R2 can be improved.

FIG. 13 shows still another variation of the light-emitting device ofthe embodiment of the present disclosure. A light-emitting device 100Ishown in FIG. 13 has a second reflective member 170 including aplurality of sloped surfaces 174 s in addition to the light-emittingelement 110A and the substrate 150. In other words, roughly speaking,the light-emitting device 100I is configured so that the secondreflective member 170 is added to the light-emitting device 100Adescribed above with reference to FIG. 1, etc.

As schematically shown in FIG. 13, the second reflective member 170 islocated over the interconnection layer 153A and the first reflectivemember 154. Here, the second reflective member 170 has a layer-shapedbase portion 172 that covers the first reflective member 154, and a wallportion 174 that extends upward from the base portion 172 in a directionaway from the substrate 150, these portions being disposed on the uppersurface 150 a of the substrate 150. In the configuration illustrated inFIG. 13, the wall portion 174, which is a structure in the shape of atriangular prism extending in the Y or X direction in the figure,includes the sloped surface 174 s that is sloped with respect to thebase portion 172. The base portion 172 of the second reflective member170 has an opening 172 z. The light-emitting element 110A, and alight-transmissive member 160 that covers the light-emitting element110A, are located inside the opening 172 z as viewed from above. Notethat the wall portion 174 may be either a hollow structure or a solidstructure.

The second reflective member 170 is typically formed of alight-transmissive resin, such as a polycarbonate (PC), PET, polymethylmethacrylate (PMMA), polypropylene (PP), or polystyrene (PS). A lightdiffusion function may be imparted to the second reflective member 170by dispersing, in a base material such as the resin, a material having arefractive index different from that of the base material. The secondreflective member 170 can be formed by performing molding with a mold,such as injection molding, extrusion molding, compression molding,vacuum molding, pressure molding, or press molding, stereolithography,or the like. For example, by applying vacuum molding to alight-transmissive sheet formed of PET or the like, thelight-transmissive sheet can be shaped so that the base portion 172, andthe wall portion 174 having the plurality of sloped surfaces 174 s, areintegrally formed. The light-transmissive sheet has a thickness of, forexample, 100-500 μm.

The sloped surfaces 174 s of the wall portion 174, which are, forexample, disposed so as to surround the periphery of the light-emittingelement 110A as viewed from above, serves as a reflective surface thatreflects upward light from the light-emitting element 110A. By disposingthe second reflective member 170 over the substrate 150, uniform lightcan be obtained in a larger region, and therefore, for example, asurface-emission light source having a high luminance and reducedluminance non-uniformity can be provided.

FIG. 14 shows an example integrated light-emitting device having atwo-dimensional array of the light-emitting devices of FIG. 13. Anintegrated light-emitting device 200A shown in FIG. 14 includes an arrayof 16 units each having a structure similar to that shown in FIG. 13.These units are disposed in a matrix of four rows and four columns inthe XY plane of the figure. As shown in FIG. 14, the plurality of slopedsurfaces 174 s each extend in the X or Y direction in the figure, andeach light-emitting element 110A is surrounded by four of the pluralityof sloped surfaces 174 s.

The integrated light-emitting device 200A, which is a surface-emissionlight source including a plurality of light emission regions arranged ina matrix of four rows and four columns, is useful as, for example, abacklight for a liquid crystal display device. As shown in FIGS. 13 and14, each light-emitting element 110A is surrounded by a plurality ofsloped surfaces 174 s, and therefore, luminance non-uniformity can beprevented or reduced in each light emission region, and even in groupsof light emission regions. Note that, of course, a similar effect can beobtained even in the case in which the second reflective member 170 iscombined with the light-emitting element 110B, 110C, or 110D instead ofthe light-emitting element 110A.

Another example integrated light-emitting device is shown in FIG. 15.Specifically, FIG. 15 is a cross-sectional view showing onelight-emitting device 100J in an integrated light-emitting device 200B.The integrated light-emitting device 200B includes a two-dimensionalarray of light-emitting devices 100J. The light-emitting device 100J isdifferent from the light-emitting device 100I of FIG. 13 in that thelight-emitting device 100J has an optical multilayer structure 180. Theoptical multilayer structure 180 includes, for example, a one-way mirror181, a diffuser 182, and at least one prism sheet 183. In the example ofFIG. 15, the optical multilayer structure 180 further includes a prismsheet 184 and a polarization sheet 185. The optical multilayer structure180 is preferably located on the side of the substrate 150 on which thelight-emitting element 110A is supported, while the prism sheet 183 ispreferably located on the light emission side. The diffuser 182 ispreferably located between the one-way mirror 181 and the prism sheet183.

The one-way mirror 181 transmits a portion of incident light from thedirection of the substrate 150 and reflects a portion of the light backto the substrate 150. FIG. 16 is a schematic plan view of the one-waymirror 181. The one-way mirror 181 includes a plurality of holes 181 hand 181 g on the main surfaces thereof. In this embodiment, the holes181 h and 181 g are a physical through hole that penetrates from onemain surface to the other main surface. In the regions of the holes 181h and 181 g, the one-way mirror 181 transmits light, substantiallywithout reflection. Therefore, by adjusting the sizes, numbers, andpositions of holes 181 h and 181 g, the one-way mirror 181 can havetwo-dimensional distributions of light transmission characteristics andlight reflection characteristics so that incident light from thedirection of the substrate 150 is emitted to the diffuser 182 with theluminance non-uniformity and color non-uniformity thereof prevented orreduced. In the case in which the one-way mirror 181 includes alight-transmissive substrate and an dielectric multilayer film supportedby the substrate, similar optical characteristics may be obtainedwithout providing holes in the substrate or providing a dielectricmultilayer film in the regions of the holes 181 h and 181 g.

In the example of FIG. 16, the holes 181 h, which are larger than theholes 181 g, are disposed over the wall portions 174 surrounding theperiphery of the light-emitting element 110A. The holes 181 g aredisposed in concentric circles around the light-emitting element 110A asthe center, and at the corners of a quadrilateral surrounded by the wallportions 174. The disposition of the holes 181 h having a largerdiameter over the wall portions 174 allows leakage of light to thesections of adjacent light-emitting elements at the boundaries of thewall portions 174, and therefore, the boundaries of the sections definedby the wall portions 174 are made less visible.

The diffuser 182 diffuses light transmitted through the one-way mirror181 in various traveling directions, resulting in a reduction inluminance non-uniformity and color non-uniformity. The prism sheets 183and 184 refract incident light to change the traveling direction of thelight so that the light is emitted in a front direction. The prismsheets 183 and 184 are disposed so that the prisms thereof areorthogonal to each other, and therefore, light is emitted in the frontdirection more accurately, whereby luminance in the front direction isincreased. For example, the polarization sheet 185 reflects the S waveof incident light and transmits the P wave of incident light, andthereby, emits light having a uniform polarized direction, so that theluminance of a specific polarized wave surface of light emitted from thelight-emitting device 100J is increased. In particular, this iseffective in the case in which the integrated light-emitting device 200Bis used as a backlight for a liquid crystal panel.

Still another example integrated light-emitting device is shown in FIG.17. Specifically, FIG. 17 is a cross-sectional view showing one oflight-emitting devices 100K included in an integrated light-emittingdevice 200C. The integrated light-emitting device 200C includes atwo-dimensional array of light-emitting devices 100K. The light-emittingdevice 100K is different from the light-emitting device 100J of FIG. 15in that the light-emitting device 100K includes the light-emittingdevice 100C. In the integrated light-emitting device 200C, thelight-emitting device 100K includes the light-transmissive member 160,and the light-emitting device 100C including the light-emitting element110C. Therefore, when the light-emitting device 100C is mounted on thesubstrate 150, it is not necessary to position the light-emittingelement 110C and the light-transmissive member 160 with respect to eachother. Therefore, compared to the case in which the light-emittingelement 110C and the light-transmissive member 160 are disposed on thesubstrate 150, the occurrence of a defective product caused by anunacceptable positioning error can be prevented or reduced. Inparticular, the integrated light-emitting device 200C includes aplurality of light-emitting devices 100K, and therefore, a manufacturingyield thereof can be effectively improved.

The integrated light-emitting devices 200A and 200B each include aplurality of light-emitting elements 110A disposed on the substrate 150.Therefore, each light-emitting element 110A can be inspected for leakagecurrent or the like with the light-emitting element 110A mounted on thesubstrate 150. This is helpful in verifying the performance of themanufactured integrated light-emitting devices 200A and 200B, repairingthe manufactured integrated light-emitting devices 200A and 200B, etc.,and thereby improving the efficiency of production of the integratedlight-emitting devices 200A and 200B.

The embodiments of the present disclosure are useful for various typesof light sources for lighting, in-vehicle light sources, light sourcesfor displays, etc. In particular, the embodiments of the presentdisclosure are advantageously applicable to backlight units forliquid-crystal display devices. A light-emitting device and integratedlight-emitting device according to an embodiment of the presentdisclosure can be suitably used in a backlight for the display device ofa mobile device, which heavily requires a reduction in thickness, asurface-emission device on which local dimming control can be performed,etc.

While exemplary embodiments of the present invention have been describedabove, it will be apparent to those skilled in the art that thedisclosed invention may be modified in numerous ways and may assume manyembodiments other than those specifically described above. Accordingly,it is intended by the appended claims to cover all modifications of theinvention that fall within the true spirit and scope of the invention.

What is claimed is:
 1. A light-emitting device comprising: alight-emitting element having an upper surface, and comprising aplurality of semiconductor light-emitting structures disposed at a sideopposite the upper surface, and electrically separated from each other,each semiconductor light-emitting structure comprising a first electrodeand a second electrode having different polarities; and a substratesupporting the light-emitting element; wherein: the plurality ofsemiconductor light-emitting structures include a first semiconductorlight-emitting structure and a second semiconductor light-emittingstructure; the substrate comprises: an interconnection layer comprising:a first interconnection portion comprising a first land, a secondinterconnection portion comprising a second land and a third land, and athird interconnection portion comprising a fourth land, and a firstreflective member covering a portion of the interconnection layer andhaving an opening; the light-emitting element is located inside theopening of the first reflective member as viewed from above; a portionof the first land is exposed in the opening of the first reflectivemember, wherein said portion of the first land is coupled to the firstelectrode of the first semiconductor light-emitting structure; a portionof the second land and a portion of the third land are exposed insidethe opening of the first reflective member, wherein said portion of thesecond land is coupled to the second electrode of the firstsemiconductor light-emitting structure, and wherein said portion of thethird land is coupled to the first electrode of the second semiconductorlight-emitting structure; and a portion of the fourth land is exposedinside the opening of the first reflective member, wherein said portionof the fourth land is coupled to the second electrode of the secondsemiconductor light-emitting structure.
 2. The light-emitting deviceaccording to claim 1, wherein: a portion of the second interconnectionportion of the interconnection layer that electrically couples thesecond land to the third land is entirely covered by the firstreflective member; and said portion of the second land is spatiallyseparated from said portion of the third land.
 3. The light-emittingdevice according to claim 1, wherein: said portions of the first,second, third, and fourth lands have a 4-fold rotational symmetricalarrangement about a center of the light-emitting element.
 4. Thelight-emitting device according to claim 2, wherein: said portions ofthe first, second, third, and fourth lands have a 4-fold rotationalsymmetrical arrangement about a center of the light-emitting element. 5.The light-emitting device according to claim 1, wherein: the pluralityof semiconductor light-emitting structures further include a thirdsemiconductor light-emitting structure disposed on the side opposite theupper surface of the light-emitting element, the third semiconductorlight-emitting structure comprising a first electrode and a secondelectrode having different polarities; the third interconnection portionof the interconnection layer further comprises a fifth land; theinterconnection layer further comprises a fourth interconnection portioncomprising a sixth land; a portion of the fifth land is exposed insidethe opening of the first reflective member, wherein said portion of thefifth land is coupled to the first electrode of the third semiconductorlight-emitting structure; and a portion of the sixth land is exposedinside the opening of the first reflective member, wherein said portionof the sixth land is coupled to the second electrode of the thirdsemiconductor light-emitting structure.
 6. The light-emitting deviceaccording to claim 5, wherein: a portion of the third interconnectionportion of the interconnection layer that electrically couples thefourth land to the fifth land is entirely covered by the firstreflective member; and said portion of the fourth land is spatiallyseparated from said portion of the fifth land.
 7. The light-emittingdevice according to claim 1, wherein: the light-emitting elementcomprises a reflective layer at an upper surface side of thelight-emitting element.
 8. The light-emitting device according to claim2, wherein: the light-emitting element comprises a reflective layer atan upper surface side of the light-emitting element.
 9. Thelight-emitting device according to claim 3, wherein: the light-emittingelement comprises a reflective layer at an upper surface side of thelight-emitting element.
 10. The light-emitting device according to claim1, further comprising: a light-transmissive member covering thelight-emitting element and a portion of the first reflective member onthe substrate.
 11. The light-emitting device according to claim 2,further comprising: a light-transmissive member covering thelight-emitting element and a portion of the first reflective member onthe substrate.
 12. The light-emitting device according to claim 3,further comprising: a light-transmissive member covering thelight-emitting element and a portion of the first reflective member onthe substrate.
 13. The light-emitting device according to claim 4,further comprising: a light-transmissive member covering thelight-emitting element and a portion of the first reflective member onthe substrate.
 14. The light-emitting device according to claim 7,further comprising: a light-transmissive member covering thelight-emitting element and a portion of the first reflective member onthe substrate.
 15. The light-emitting device according to claim 10,wherein: the light-transmissive member has a peak portion in a shape ofa ring as viewed from above.
 16. The light-emitting device according toclaim 1, further comprising: a second reflective member located over theinterconnection layer and the first reflective member, the secondreflective member having a plurality of sloped surfaces surrounding thelight-emitting element as viewed from above.
 17. The light-emittingdevice according to claim 7, further comprising: a second reflectivemember located over the interconnection layer and the first reflectivemember, the second reflective member having a plurality of slopedsurfaces surrounding the light-emitting element as viewed from above.18. The light-emitting device according to claim 10, further comprising:a second reflective member located over the interconnection layer andthe first reflective member, the second reflective member having aplurality of sloped surfaces surrounding the light-emitting element asviewed from above.
 19. The light-emitting device according to claim 1,wherein: a distance between two adjacent ones of the first, second,third, and fourth lands of the interconnection layer is greater in aregion located in the opening of the first reflective member and outsidethe light-emitting element as viewed from above than in a region underthe light-emitting element.
 20. The light-emitting device according toclaim 19, wherein: the distance between said two adjacent ones of thefirst, second, third, and fourth lands in the opening of the firstreflective member and outside the light-emitting element as viewed fromabove becomes greater stepwise or continuously from a side closer to thelight-emitting element to a side further from the light-emittingelement.